1. Field of the Invention
The present invention relates generally to a voice warning system for an automotive vehicle, and more particularly to a voice warning system such that information is indicated to the driver in voice form only once when car-radio sound volume is reduced and, thereafter, an alarm sound is produced until the driver takes a proper action.
2. Description of the Prior Art
Heretofore, there have been used various warning lamps and alarm buzzers or chimes for informing the driver of various warning information on, for instance, unclosed door, seat-belt putting-on, lamp putting-out, shortage of fuel, coolant, battery liquid, washer liquid and so on.
However, since such lamps inform the driver of various information visually, it is sometimes easy for the driver to fail to notice the warning and fail to take appropriate actions against the warning.
On the other hand, in the case of alarm sound, although a driver's attention is well called to the sound, the driver cannot in general distinguish between many different alarm sounds and, therefore, it is impossible to indicate complex information to the driver. For example, if used with a speed warning system which can warn the driver of an excessive speed when an actual vehicle speed exceeds a predetermined set speed, the alarm sound cannot inform the driver of how much the vehicle speed exceeds the set speed.
Therefore, the present inventors have proposed a voice warning system by which various warning information is indicated to the driver, in voice form, accurately and correctly. When this system is used for warning vehicle speed, it is possible to inform the driver of the degree of the excessive speed.
In this system, however, it is very noisy to repeat the same voice information again and again and it is very dangerous to output voice information only once, because the driver may fail to notice the warning or forget it.
In addition, in the case other audio devices are provided in the same vehicle, although it is necessary to reduce the sound volume from the audio devices, it is not preferable to reduce the sound volume whenever the same voice information is repeated.